In some compressors, in order to reduce compressor wear and extend the service life of the compressor, a sufficient amount of lubricating oil is poured into the compressor, to provide adequate lubrication for the various components of the compressor. However, in actual applications, if the quality of the lubricating oil in a compressor deteriorates, this might result in failure of the lubricating function of the lubricating oil in the compressor.
Indices associated with the quality of lubricating oil in a compressor include the degree of dilution of the lubricating oil, foreign substance mixed into the lubricating oil, oxidation or carbonization of the lubricating oil, etc.
If the degree of dilution of lubricating oil in a compressor is too high, i.e. an excessive amount of coolant has mixed into the lubricating oil in the compressor, the concentration of the lubricating oil in the compressor will be too low as a result. This will cause a reduction in the viscosity of the lubricating oil; once the viscosity of the lubricating oil is reduced, serious wear to the bearings of the compressor will result. Thus, once the degree of dilution of lubricating oil is higher than a warning level, it is necessary to immediately stop the compressor or reduce the degree of dilution of the lubricating oil. In the prior art, some of the coolant that has mixed into the lubricating oil can generally be evaporated out by heating the lubricating oil, so as to reduce the degree of dilution of the lubricating oil.
If foreign substance, for instance iron fragments that have fallen off compressor bearings, becomes mixed into lubricating oil, this will aggravate wear of compressor components. Once iron fragments are mixed into lubricating oil, it is necessary to immediately stop the compressor, and remove the iron fragments from the lubricating oil.
If lubricating oil is oxidized or carbonized, the lubricating oil will lose its lubricating function, and this will lead to rapid wear of the compressor, shortening the service life of the compressor. Once lubricating oil is oxidized or carbonized, it is necessary to immediately stop the compressor, and replace the lubricating oil with new lubricating oil.
In summary, in order to ensure that a compressor can operate safely, the quality of lubricating oil in the compressor must be monitored on-line in real time.
Regarding the on-line real-time monitoring of the quality of lubricating oil in a compressor, in the prior art, the quality of lubricating oil is generally monitored by measuring the viscosity, density or contaminants of the lubricating oil. However, an existing monitoring apparatus for monitoring the quality of lubricating oil by measuring the viscosity, density or contaminants of the lubricating oil has a very high cost; the price of the monitoring apparatus is 400,000 to 1.6 million RMB. Furthermore, the installation of such an existing monitoring apparatus is very complex, and large amounts of data need to be processed, so the detection speed is slow. At present, such a monitoring apparatus is only suitable for laboratory tests; it cannot yet be used industrially.